He e we p esen an enzyme kine ic model (EKM) o espi a o y oxygen consump ion based on he subs a e con ol o
he ETS (Fig. 2 and 3). I a gues ha R is con olled by he maximum eloci y, Vmax, o he enzyme eac ions ha con ols
he p ocess (i.e., he ETS), he empe a u e, and he subs a e a ailabili y, S (Fig. 3). Kine ics o his he mal-subs a e
egula ion a e desc ibed by he A henius and Michaelis-Men en equa ions. The EKM equa ion akes he o m:
whe e Ea is he mola A henius ac i a ion ene gy, Rg is he mola gas cons an , Km is he Michaelis-Men en cons an , and
T is empe a u e.
He e we apply he EKM and he MTE o p edic a espi a ion imes-p o ile h oughou he exponen ial, s eady s a e, and
nu ien -limi ed phases o he ma ine bac e ium Vib io na iegens in an ace a e-based cul u e (Fig. 1). Bo h models we e
es ed by compa ing hei ou pu wi h he measu ed RO2 ime-p o ile (Fig. 4 op). They we e e alua ed quan i a i ely by
leas -squa e eg ession analysis (Fig.4 bo om). When he p edic i e capabili y o bo h models was compa ed, se ious laws
in he MTE ende ed i inaccu a e du ing nu ien limi a ion. In con as , he EKM wo ked well h oughou he en i e pe iod o
he expe imen . Resul s sugges ha espi a o y con ol is achie ed h ough changes in he in i o, νETS , ac i i y o he ETS
by subs a e modula ion o he in i o ETS, AETS, (Vmax). We conclude ha EKM holds p omise o p edic ing espi a ion a
he di e en physiological s a es and ime-scales impo an o mic obiological s udies.
)(
)
)(
(
max
1
01
SK
eSV
R
m
TTR
E
g
a
M. Bo ja Aguia -González1, May Gómez2, Elisa Be dale 3, Syl ie Roy4 & Ted Packa d2
1 Dp o de Física, Uni e sidad de Las Palmas de G an Cana ia, Las Palmas de G an Cana ia, Spain.
2 Dp o de Biología, Uni e sidad de Las Palmas de G an Cana ia, Las Palmas de G an Cana ia, Spain.
3 Ins i u de Ciències del Ma (CSIC), Ba celona, Spain.
4 3579A Delson d i e, P.O. Box 348, Na an, On a io K4B 1J5, Canada.
Can he Me abolic Theo y o Ecology p edic espi a ion in
ma ine bac e ia?
Respi a o y oxygen consump ion is caused by enzyma ic ac i i y o he espi a o y elec on ans e sys em (ETS). Howe e , in spi e o
his unde s anding, espi a ion models con inue o be based on allome ic equa ions ela ing espi a ion o body size, body su ace, o
biomass. The Me abolic Theo y o Ecology (MTE) is a ecen example. I is based on Kleibe ’s Law ela ing espi a ion (R) and biomass
(M) in he o m, R = K1 M3/4, whe e K1 is a cons an . This law holds because biomass packages he ETS. Consequen ly, we ha e been
p oposing o bypass biomass and model espi a ion di ec ly om i s causal ela ionship wi h he ETS ac i i y (R = (ETS)).
Table 1. Kine ic pa ame e s ha we e used o calcula e he in i o ETS ac i i y
(νETS ) and he in acellula NADH and NADPH concen a ions.
Du ing Nu ien Limi a ion
MTE does no p edic
bac e ia espi a ion!
Fig.1 Expe imen VnAc110593 showing ime-cou se obse a ions o AETS,
RO2, p o ein and ace a e. Fig. 2 The inspi a ion o conside ing Michaelis-Men en as he
h o le mechanism o espi a ion. He e espi a ion alls in pa allel
wi h he nu ien supply.
Fig.3 Modelled in acellula NADH and NADPH o expe imen
VnAc110593. P is ace a e, M is cell p o ein and δ, ω, λ and η a e
cons an s (Table 1).
Enzyme Kine ic Model (EKM)
Fig. 4 (a) Modelled ime-p o ile o RO2 based on in i o ETS om EKM; (b) EKM
P edic ed-Respi a ion e sus Respi a ion; (c) Modelled ime-p o ile o RO2
based on allome ic ela ionship (cell p o ein) om MTE.; (d) MTE P edic ed-
Respi a ion e sus Respi a ion.
A con ibu ion om ICM-CSIC, BLOS, ULPGC, and he p ojec s: EXOME (CTM-2008-01616), and OITHONA
(CTM2007-60052). Fi s au ho has been suppo ed by a FPU g an om he Spanish Minis y o Science and
Inno a ion.
(a) (c)
(b) (d)